Abstract:Laser surface alloying with C and C+Nb was used to modify the surface properties of Ti-46Al-2Cr-1.5Nb-lV alloy. The microstructure of the laser alloyed surface layer was studied as function of laser processing parameters. The oxidation resistance properties of the original alloy and the samples with the laser surface treatment with C and C+ Nb at high temperature were investigated. The results indicate that, by laser alloying with with C and C+Nb, the particles of TiC were "in-situ" produced in the laser surface layer. Nb exists in the TiAl matrix as the solute atom. The size, shape and distribution of TiC are strongly dependent on the laser processing parameters. By laser surface alloying with C and C+Nb powders, the oxidation resistance is improved obviously, and the sample alloying with C+Nb exhibits the best oxidation resistance.